{
volScalarField alphaEff_1("alphaEff_1",turbulence->nu()/Pr_1);

fvScalarMatrix TEqn_1
(
fvm::ddt(T_1)
+ fvm::div(phi, T_1)
- fvm::laplacian(alphaEff_1, T_1)
+ U.component(0)*gamma_1     //if your flow is periodic in y or z directions, e.g. component(1) or  //component(2).
);

TEqn_1.solve();
}
